Please create a new ticket to track the issue unless your patch is a patch for an issue that is already ticketed.

Then run the following darcs commands to generate a darcs patch file named {{{WHAT.txt}}}:

{{{
  darcs record
  darcs send -o WHAT.txt
}}}

And attach it to the ticket.

Please use a filename like *.txt (instead of *.patch or *.diff) so that Trac will let other
developers view it without first requiring them to download it first. (Trac's content-type logic maps
*.patch and *.diff to some application/blahblah MIME type, which it refuses to display as HTML)

If you don't have darcs or don't want to use it, just attach a normal old diff.

== discussion ==

If you have an actual diff (as opposed to a darcs patch created with 'darcs send'), then .diff is
good, because Trac knows how to render them. At least it does on the attachements I looked at
on #684 . I haven't checked to see what a darcs patch file attached with a .diff filename looks like,
I think it could get pretty ugly.
On the other hand, downloading the diff with "Download Original Format" gets a content-type which firefox
insists upon saving instead of displaying. I think I'm ok with that.. what I care about is being able to
review the change easily, and Trac's diff markup is pretty good.
-warner